Special features: Battery SAVE mode with BMS reset. Starts from 0.5V with continuous monitoring / testing of charge acceptance or bad / shorted cell condition. Unnecessary (and unsafe) charging of a bad battery is prevented.safeTº automatic charge rate adjustment to ambient temperature sensed at the charger. Reduced charging below freezing, no charging if temperature is below -20ºC/-4ºF (can damage lithium batteries). Ampmatic. Microprocessor adjusts current to ideal LiFePO4 charge curve to match battery size / condition, for fastest and most complete charge. Protection against incorrect voltage selection. With 16V selected and a 12.8V (4s) battery is connected OptiMate 7 LFP Select will immediately warn that a low voltage is sensed and then not proceed to charging. USER must confirm the nominal voltage of the connected battery is 16V (5s) before SAVE mode activates. During SAVE mode the charge curve is tracked, if the battery appears to be less than a 5-series 16V battery, it will stop charging.